Levi Krystosek, 11, has a rare form of dwarfism called Jansen's Metaphysical Chondrodysplasia, which affects the growth of bones and causes considerable pain, meaning he is only 38 inches tall.

There are approximately only 30 known cases of JMC in the world, and five genetically confirmed cases in the US. At just eight days old, doctors told Levi’s parents, Dona and Joseph, from Ocean Springs, Mississippi that their son was probably going to die.

Determined their son would survive, the Krystoseks had to feed Levi every two hours just to try and build up his strength.

Then when he started school, Levi failed Kindergarten twice and was put into a special needs class – but in fact an effect of JMC is optic nerve atrophy. All he needed was to sit near the front of the class and have his worksheets blown up so he could read them.

Little Levi, as he is known by friends and family, was finally put into general education classes in the middle of 3rd grade – catching up three school years in one year - and is now in 5th grade and has started playing the piano too.

Mum Dona, 47, told Barcroft TV: “When he was younger he’d say I can’t wait to get another birthday so I can get taller and I had to explain to him just because you get another birthday it means you are going to get older but it doesn’t mean you are going to get taller.”

“He did drop through the cracks and he’s catching up for it now.”

Orthopedic surgeon Dr William MacKenzie, who has known the Krystosek family for over eight years, said. “JMC is an extremely rare form of skeletal dysplasia. It happens in about one in a million live births, so that makes Levi pretty special.

“It is caused by an abnormal receptor in the bone which interferes the way the bone grows and develops.”

Because the body doesn’t process calcium as it should, the bones get bendy and crooked – ‘wonky bones’ as the Krystoseks call them.

It took a year for Dona and Joseph to receive the diagnosis of JMC for their son; initially they were relieved to learn Levi had a form of dwarfism unaware of the future complications.

Dona said: “The doctor came in to the hospital room and said: ‘I need you to sit down.’ And he sat me down and he told me that Levi had Jansen’s.

“I was relived to have knowledge of what he had. But then it made me sad because the more that the doctor explained what was going to happen, it was hard. It sounded very painful.

“I had a lot of questions. When we found out that Levi had Jansen’s I wanted to know what caused it? Was there a cure? And there is not a cure for Jansen’s. Were there other cases? Were there other children that lived nearby?

"I just knew at that moment that I was going to do everything I could for him to get the best quality of life for him."

Since then the family have had to get used to making many visits to hospitals across the country.

Levi said: “I actually have to go to a couple of doctors for different things like to my eye doctor in Birmingham because I can only see out of this eye and then I go to Chicago and the children’s hospital there.”

The family have had to fly back and forth to various specialists across the country all of Levi’s life. Thanks to a charity called Miracle Flights they’ve been able to afford the multiple trips.

On his latest visit to the Nemours Children's Hospital in Wilmington, Delaware, Levi was fitted with a back brace to help to try and straighten out his spine.

If the brace is successful it could help add crucial inches to Levi’s height. At the moment Levi is 3ft1 tall (the average height for an 11-year-old boy is approximately 4 ft 7.

While Levi’s small stature is the most obvious physical sign of JMC, the condition has also had an impact on his internal organs. And in spite of his positive nature, Levi is constantly in pain.

“He has a high tolerance for pain so when he complains I know he’s really hurting if he’s out walking around or playing somewhere he’ll just sit down and rest. When he says he’s in pain that’s when I call the doctor.”

Because of his condition Levi also cannot play any contact sports – even a friendly tussle with playmates could be life threatening. Levi said: “how it makes me different from the other kids at school is I can't play contact sports.”

Donna added: “He is not allowed to jump. He has to be very careful. A simple headlock could be catastrophic for him.

“Levi uses his wheelchair for long distances. He uses it mostly at school. We use a special needs stroller right now when we are out in public. He just received a power wheelchair."

Because there is such a low number of genetically confirmed cases of JMC there is limited information on it. Dona and her family are actively involved with the Jansen’s Foundation, which not only bring together those who also have the condition but also to raise awareness and push for more research.

Dona said: “We’ve always been honest with him about everything. He understands the condition and that doctors are trying to find a cure but it might not help him. It’s more a bout finding a cure for the pain levels than the height.”

“My hopes for Levi in the future are that he grows up and he gets married.

"I want him to be a normal, happy, healthy kid. I want him to do as much as he can do.”